1. Field of the Invention
This invention relates to a door opener error-start prevention device, and particularly to a device which solves a jammed problem by itself, and which then makes the door opener reverse and then return back to its original position, when a door opener and a latch device are jammed, and rotation of a door opener is hindered, because of error-start.
2. Description of the Prior Art
Referring to FIG. 1, as an example illustration, for all rolling doors or sectional door or doors that move up and down in vertical direction, rolling doors that move in horizontal direction, sectional doors that moves in a manner that is parallel to the ground or other doors that are opened or closed in an electrical operation manner. For safety reason, a conventional door opener is usually provided with a latch device 2 on one side of the rolling door 1, the purpose of which is to avoid being externally enforced opened either by a jack or by other means, after the door is closed. The latch device 2 of the rolling door 1 is locked from outside, after the door is closed. However, the latch device 2 must be unlocked at first, before the switch 3 for the rolling door 1 is switched on. In some cases, users often forget to unlock the latch device 2 before switching on the switch 3 for the rolling door 1. As a result, the rolling door 1 is jammed with the latch pin of the latch device 2, and this will result in switching on safety device and switching off the electrical power. In this case, neither can the rolling door 1 be opened, nor can the latch device 2 be unlocked. The only solution is to eliminate the jammed condition between the rolling door 1 and the latch device 2, i.e., the rolling door 1 must return back to its original loose status, and then the latch device 2 can be unlocked and the switch 3 of the door opener can be switched on again. Therefore, the design of conventional rolling door 1 still has room for improvement.